Electrical socket



March 28, 1967 A P. DEVITO ELECTRICAL SOCKET 2 Sheets-Sheet l Filed May 27, 1965 INVENTOR M,7@MW;%W WTTORNEYS United States Patent 3,311,865 ELECTRHCAL SOCKET Albert P. Devito, Niles, lllL, assignor to Alcon Metal Products, lnc., Chicago, llL, a corporation of Delaware Filed May 27, 1965, Ser. No. 459,159 9 Claims. (Cl. 339-132) This invention relates to improvements in electrical sockets and more particularly sockets of the multiple receptacle type adapted to receive up to a maximum plurality of connector pins.

One of the problems with sockets of this type is the attachment and soldering of lead wires to the multiple receptacles. customarily, this has required manual soldering of each lead wire.

An important object of the present invention is to provide a new and improved multiple receptacle socket construction adapted for simultaneous dip soldering of all leads.

A further object of the invention is to provide a new and improved multiple receptacle socket structure having novel means for mounting the receptacles and associated lead connectors or terminals.

Still another object of the invention is to provide novel lead connector means for the pin-receptacles of multireceptacle sockets.

A still further object of the invention is to provide a new and improved multi-receptacle chassis-mounted socket construction.

Other objects, features and advantages of the present invention will be readily apparent from the following detailed description of certain preferred embodiments thereof taken in conjunction with the accompanying drawings in which:

FIGURE 1 is a bottom plan view of an electrical socket structure embodying features of the invention;

FIGURE 2 is a top plan view of the socket structure of FIGURE 1;

FIGURE 3 is an inverted side elevational view of the socket structure and demonstrating how simultaneous soldering of leads in the solder well terminals of all of the connectors can be effected;

FIGURE 4 is a fragmentary sectional elevational detailed view taken substantially on the line IV-lV of FIG- URE 1;

FIGURE 5 is a fragmentary plan view of a chassis mount for the socket assembly;

FIGURE 6 is a top plan view of a modified socket structure embodying features of the invention; and

FIGURE 7 is a side elevational view partly in section taken substantially on the line VIl-Vll of FIGURE 6.

In FIGURES 14, a practical embodiment 10 of the socket structure of the present invention comprises a body 11 which is desirably molded or cast from a suitable dielectric material such as one of the plastics commonly used for this purpose, of which the phenolic condensation product commercially obtainable as Bakelite is an example. In the form shown, comprising what may be referred to as a top mounted socket, the body 11 is of generally circular thick disk-like form having thereabout a radial outwardly extending mounting flange 12 including a pair of oppositely extending attachment ears 13, each of which has therethrough a suitable aperture ld through which may extend an attaching rivet or the like 15 (FIG- URE 4) for securing the socket assembly to a supporting base such as a chassis panel 17 having complementary attachment member receiving holes 18 therethrough (FIGURES 4 and 5). As shown, the flange 12 is located adjacent to one end of the body 11 and spaced from the opposite end of the body.

3,3 l L865 Patented Mar. 2%, i355 On the mounting panel 15, the socket assembly 10 has its front or top face accessibly disposed on one side of the panel 17, while the rear or lower face of the assembly, and more particularly the face of the body 11 is nearest the flange 12 is accessible from the opposite or lower face of the mounting panel. To this end, the mounting panel 15 has a clearance aperture 19 therethrough centered between the attachment holes 18 and of a diameter complementary to and receptive of an annular flange Ztl extending axially from the flange 12.

To provide for auxiliary or prime attachment of the body 11 to the supporting panel 17, a generally keyholeshaped recess is provided in the back face of the body and including a generally radial portion 21 extending through the flange 2t) and at its inner end including a circular portion 22 coaxial with the body 11. Receptive in the keyhole recess is a generally keyhole-shaped integral attachment projection or arm extending into the receiving aperture 1% and including a generally radially extending arm 23 receivable in the recess portion 21, with an annular head portion 24 coaxial with the aperture 19 complementary to and receptive in the recess portion 22. Aligned fastener holes 25 and 27 in respectively the attachment head portion 2a and the body 11 are receptive of a fastener such as a rivet 23. This attachment is facilitated by a deep well recess 29 concentrically in the front face of the body 11, with a relatively thin attachment web or partition 35} separating the well recess from the attachment head-receiving recess 22 in the back face of the body.

For receiving the connector pins of an electrical connector, the body ll has a suitable number of pin-receiving bores 31 extending in an axial direction therethrough spaced inwardly from the perimeter of, and located on a circle concentric with the center of, the body. In the illustrated instance, there are twelve of the pin bores 31, for convenience identified by suitable and preferably numerical legends or indicia 32 which may be molded on the back end of the body adjacent to the respective pin bores, as shown in FIGURE 1.

Means are provided to facilitate alignment of electrical connector or tube socket pins with the pin socket bores 3i, comprising at the front or entry end of each of the bores a flaring mouth outwardly opening lead-in annular ca-m surface 33. These individual lead-in surfaces open into a generally annular groove 34 recessed in the front end face of the body ll, with the side walls defining the groove sloping inwardly to afford lead-in cam surfaces directed toward the lead-in surfaces 33. In addition, preferably between the 1 and 12 pin socket bores 31 an orientation land 35 across the groove 34 provides a space which is slightly greater than the uniform spacing between adjacent ones of the bores 31 and has inwardly sloping lead-in cam surfaces 37 by which the respective l and 12 pins of a complementary electrical connector are guided into their receiving socket bores and assist in effecting proper torsional orientation of the connector with the socket bores in assembly.

Within each of the pin bores 31 is a respective generally tubular electrically engageable receptacle 38 having its frictional pin-gripping necked flaring mouthed front end portion suitably adjacent to the inner end of the associated lead-in surface 33 and its back end substantially spaced from the back end of the pin bore. Mounting of the receptacle 33 is effected by inserting it through the open back end of its pin bore, with an angular, generally L-shaped tail piece 39 integral with the back end of the receptacle defining the front end orientation of the receptacle to the lead-in 33, by engagement of the laterally extending portion of the tail piece against the back end face of the body 11. Retention of the receptacle 38 against rearward displacement is effected by means of a longitudinally stiff but laterally resiliently flexible detent finger 40 extending from adjacent juncture of the tail piece 39 with the receptacle 38 and angled laterally to engage against a frontwardly facing stop shoulder 41 provided at the proper place in the length of the bore 31, adjacent to the back end of the bore. Normally, the detent finger 40 projects at least to an interlock position laterally from the adjacent axial arm of the tail piece 39, and as the receptacle 38 is inserted into position by axial movement from the back toward the front within the pin bore 31, the detent finger compressibly deflects toward the tail piece arm while in engagement with the wall of the bore 31 rearwardly from the interlock shoulder 41 and then snaps into engagement with the interlock shoulder as the tip of the finger moves forwardly relative to the shoulder.

For attachment of electrical leads to the respective receptacles 38, each of them is provided with a tubular terminal 42, desirably integrally joined thereto by means of the tail piece 39. Attachment of the tail piece 39 to the terminal 42 is at the back edge of the terminal which extends on a spaced parallel axis to its receptacle 38 and in the same general orientation, affording a substantially U-shaped unit connected by the angular tail piece 39. Where, as is economically desirable, the receptacle 38, the tail piece 39 and the terminal 42 are made as a one piece sheet metal stamping, the tail piece 39 comprises a relatively thin sheet metal strip.

Mounting of the terminal 42 is within a bore 43 located radially outwardly in paired alignment with the associated pin bore 31 and extending at least partially through the lateral flange 12 and inwardly adjacent to the axial flange 20. In this embodiment of the invention, the terminal bore 43 is also partially in the body 11 and opens outwardly from the outer perimeter of the body along the length of the bore forwardly from the lateral flange 12 whereby a substantial front end portion of the terminal 42 is exposed at the outer perimeter of the socket body, as best seen in FIGURES 2, 3 and 4. Desirably each of the connector terminals 42 has a rearwardly extending normally outwardly divergent spring stabilizer finger projection 42a on the opposite side from the tail piece 39 and thrusting against the flange 20, whereby to effect an interlock bias toward the interlock detent 40.

Assembly of individual or multiple electrical leads 44 with the individual terminals 42 is effected by inserting the stripped end portions of the leads into the respective selected terminals from the open back ends thereof accessible from the back end of the socket assembly as seen in FIGURE 1. Over-travel of the leading ends of the electrical leads beyond the ends of the terminals 42 is stopped by respective overhanging shoulder portions 45 on the front end of the body 11. By 'having the front end of the terminal 42 spaced a limited distance from the shoulder 45, as determined by the limiting engagement of the connecting tail piece 39 with the body 11 as shown, soldering of the exposed end portion of the associated lead 44 to the terminal 42 is facilitated. Efiiciency of the soldered connection is enhanced by a soldering lug 47 extending integrally from the inner side of the front end of the terminal 42.

For retaining the inserted electrical leads 44 at least after initial insertion thereof into the respective terminal 42 and until the leads have been thoroughly anchored by soldering, each of the terminals 42 is desirably provided with one or more, and in this instance shown as a plurality of forwardly extending sharp-tip integral gripping prongs 48 of substantially triangular form having their base ends integral with the rear portion of the terminal 42 and extending generally inwardly convergently a substantial distance forwardly beyond the front face of the flange 12. Thereby the strike-out apertures 49 about the inwardly deflected front end portions of the prongs 48 4. are generously exposed forwardly from the flange 12 to receive lead-anchoring solder.

Soldering of all of the leads 44 to their connectors 42 is adapted to be effected simultaneously by simply dipping the front. end portion of the body 11 into a body of molten solder S as schematically shown in FIGURE 3. By havingthe solder at a constant level under a gauging fixture member 50 having a dip hole 51 just large enough to afford ample clearance for easy projection therethrough of the socket assembly forwardly from the lateral flange 12, simultaneous soldering of all of the leads to the connectors is effected by the simple maneuver of inverting the socket assembly 10 with or without the leads 44 in place and inserting the front end portion through the dip opening 51, with the depth of the dipping being gauged by engagement of the flange 12 and more particularly the ears 13 against the gauging member 50. To prevent solder from entering the pin bores 31 and possibly blocking the mouth ends of the receptacles 38, a masking disk 52 is applied reasonably firmly onto and across the front face of the body 11 to close the groove 34. This masking disk is made from a solder-repellent material, as is the socket body 11. Operative retention of the masking disk 52 may be effected in any suitable manner such as by frictional retaining clip or plug structure, as may be preferred, enabling quick attachment and removal.

Where the leads 44 are preassembled with the socket 10 before soldering, a virtually instantaneous dip into the molten solder S enables the solder to flow into coating engagement with the terminals 42 and the leads 44, the soldering lugs 47 and into the terminal side wall openings 49 affording access by the solder to the leads within the terminals. If preferred, of course, the socket assembly 10 may be mounted in the dipping position on the dip gauge 50 and the leads then assembled into the selected terminals 42, since the indicia 32 will be visible on the up ended back end of the body 11, so that conformance to a wiring diagram may be effected. Desirably, the solder bath S has floating thereon suitable molten flux F so that the flux coats the parts to be soldered incident to insertion thereof into the solder bath. As the socket 10 is withdrawn from the solder bath, it is self-draining so that minimum effective solder is used in the soldering process.

Although as shown in FIGURE 3 the socket 10 is not mounted on the supporting panel 17, it should be understood that the dip soldering method described is adapted to be practiced with the socket already mounted on the supporting chassis panel 17, if desired.

In the modification of FIGURES 6 and 7, a substantially similar multi-receptacle socket assembly 60 is depicted including a preferably circular body 61 made of suitable moldable o-r castable dielectric material such as plastic and having adjacent to its back end, and spaced from its front or opposite end, a lateral mounting flange 62 provided with oppositely extending ears 63 having therethrough respective apertures 64. Projecting from the back face of the flange 62 is an annular centering flange 65 adapted to extend through a locating aperture in a chassis mounting panel, similar to that described for the socket 10 and comprising the panel 17. For receiving the attachment extension of the panel an annularly radially opening slot recess 67 through the flange 65 opens at its inner end into a central recess 68 at the back side of an attachment web flange 69 having therethrough an attachment member receiving central aperture 70 and separating the recess 68 from a deeper forwardly opening access recess 71.

An annular series of pin bores 72 is provided to the body 61 and may be individually identified by suitable indicia such as the number indicia 32 of FIGURE 1. A lead-in flaring cam mouth 73 at the front end of each of the pin bores 72 opens into a generally circular concentric groove 74 in the front end face of the body 61, with a pin orientation land 75 across the groove between two of the pin bores similarly and for the same purpose as its counterpart in the socket and provided with sloping cam lead-in surfaces 77.

Within the respective pin bores 72 are mounted respective tubular receptacles '78 having position-orienting respective integral generally L-shaped tail pieces 79 defining the forward position of the associated receptacle while a respective rearwardly projecting interlock detent tongue or finger 80 normally extending at its tip laterally relative to the associated tail piece arm engages a forwardly facing detent shoulder 81 provided in the wall of the associated pin bore 72. Also attached to the tail piece 79 is a respective tubular lead-receiving terminal 82, in each instance, mounted in an axially extending bore 83 in radially outward alignment with the associated pin bore 72 and, in this instance, extending through the lateral flange 62 slightly spaced from the adjacent annular outer perimeter of the relatively elongated body 61 and whereby the major extent of the terminal 82 is exposed about its entire perimeter forwardly from the flange 62.

Assembly of electrcial leads into the terminals 82 is through their readily accessible open back ends. Overriding of the leading ends of the leads is prevented by enclosure flange structure 84 integral with and extending in lead-stopping relation across the front ends of the terminals which thus provide lead-receiving sockets. Temporary withdrawal of the leads from the terminals is prevented by at least one and preferably a plurality of inwardly converging, forwardly extending prongs 85 struck from the respective walls defining the terminals and leaving corresponding strike-out and solder-entry openings 87.

Dip soldering of the socket assembly 60 is adapted to be effected in the same manner and with the same method as described in relation to the socket 10, having reference to FIGURE 3. When dip soldering the socket assembly 6%, only the front end of the body 61, and more par- ,ticularly the groove 74 is covered while the adjacent ends of the tubular terminals 82 are left free and fully exposed to the solder bath. Thereby, during dip soldering, the solder can enter freely into the terminals 82 through the wall openings 87. Entry of the fluid solder is also facilitated by the provision of an end entry opening 88 through and between the front end closure or stop flanges 84, and by having the stop flanges so constructed that there is a solder entry gap 89 at the inner side of the terminal head. These end openings 88 and 89 also afford drainage for excess solder as the socket assembly is removed from the solder bath.

As a desirable feature of the socket assembly 60, one or more desirably conical lug electrical lead terminals 90 may be connected to the ears 63. For this purpose, the terminals 90 are of tubular form, open at both ends and provided with a respective base end portion 91 which is received in the aperture 64 through the associated car 63. For retaining the terminal 90 in place, the tubular base portion 91 is provided on its free extremity with bendable retaining lug flanges 92 which are, after assembly of the terminal 90 with the car 63, bent from an initially axially extending position radially outwardly into retaining engagement with a rearwardly facing shoulder defined in an annular rabbet groove recess 93 in which the retaining lug flanges are disposed within the back face plane of the flange 62 whereby to avoid interference with flush mounting of such face against a mounting panel. Retainingly opposing the lug flanges 92 in spaced relation at the opposite, proximal end of the base portion 91 is an annular outwardly projecting shoulder rib 94 which seats in an annular rabbet groove 95 in the front face of the flange 62 about the aperture 64. Through this arrangement, each of the terminals 90 is mounted to project with its major body portion frontwardly on the socket 60 similarly as, and in substantially coextensive relation to the terminals 82.

Assembly of terminal end portions of electrical leads into the terminals 90 is through the rear open ends of the base end portions 91 of the terminals. Overrunning of the leading ends of the electrical leads from the front or crown ends of the terminals is limited by respective combination stop flanges and solder lugs 97 desirably formed integrally with the associated terminal. These stop-solder lugs 97 extend integrally from one side of the terminal into overlying relation to the open front or crown end of the terminal, and with a limited solder entry gap between the lug and the adjacent free crown edges of the terminal. Thus, by having the terminals 90 of substantially the same overall length as the terminals 82, dip soldering of the leads in the terminals 90 is effected simultaneously with dip soldering of the leads associated with the terminals 82. For convenience in soldering electrical wires onto the lugs 9-7, they are desirably provided with respective indented grooves 98.

For at least initial retention of leads inserted into the terminals 90, each of the terminals is desirably provided with at least one, and preferably a plurality of inwardly converging, forwardly extending retainer prongs 99 struck out of the wall defining the body of the associated terminal and leaving generally triangularly-shaped strike-out openings 100 which may assist in the dip soldering access of solder into the terminal. In addition, electrical contact and soldering of the terminal end portions of the leads within the terminal 90 is enhanced by generally frusto-conical tapering of the terminal body toward its crown end, tending to crowd the terminal lead ends against the inner surface of the crown end portion of the terminal. On the other hand, additional internal clearance for insertion passage of the leading ends of the electric wires toward the crown end of the terminals is atforded by an intermediate outwardly projecting portion or diametrical bulging enlargement 101 of the tubular terminal body intermediate the shoulder 94 and the stop means flange 97 but closer to the shoulder 94.

It will be understood that modifications and variations may be effected without departing from the scope of the novel concepts of the present invention.

I claim as my invention:

1. In combination in an electrical socket assembly of the character described,

a dielectric body having a perimeter with a lateral flange thereabout extending outwardly from said perimeter adjacent to one end of the body and spaced from the opposite end of the body,

an annular series of receptacle bores opening through the opposite ends of said body spaced inwardly from said perimeter,

an annular series of corresponding terminal bores at least partially in and extending entirely through said flange adjacent to the perimeter of said body,

respective receptacle-terminal units each comprising a pin receptacle and a terminal and a connecting tail piece affording a generally U-shaped structure with the receptacle in one of the receptacle bores and the terminal in and extending through the corresponding terminal bore with a substantial portion of the terminal exposed outwardly from said perimeter and the tail piece extending between the bores and connecting the receptacle and terminal,

means cooperating with the tail piece in each instance to retain the associated unit in place, each receptacle having a pin-receiving mouth accessible through an access end of the associated receptacle bore and the associated terminal having an open end accessible from the opposite end of the corresponding terminal bore,

said body having a substantially flat end face with a generally annular groove therein into which said access ends of the receptacle bores open, and

means in said grooves for guiding connector pins into said receptacles.

2. An electrical socket construction of the character described comprising:

a dielectric body having opposite ends and perimeter extending between said ends,

a series of pin-receiving bores through said body adjacent to said perimeter and opening through the opposite ends,

respective pin receptacles in said bores and having leadreceiving terminals electrically connected thereto and extending in position adjacent to and substantially exposed outwardly from said perimeter,

said terminals having the opposite ends open, shoulder means on said body overlying one of said ends of the terminals and the opposite ends of the terminals being accessible for introduction of electrical lead ends thereinto, and

said shoulder means being spaced from the adjacent ends of the terminals so that the leads can be soldered to all of the terminals simultaneously by dip soldering wherein the end portions of the terminals adjacent to the shoulder means are all simultaneously dipped into a solder bath.

3. In combination,

a socket assembly comprising a dielectric body having front and back faces and provided with a lateral mounting flange on its back end portion including an axially extending centering flange projecting rearwardly therefrom,

a plurality of electrical receptacles mounted in said body and having pin-receiving mouth ends accessible from the front face of the body and provided with electrical terminals at least partially mounted in said mounting flange and having lead-receiving openings accessible from the back of the body,

a mounting panel having an aperture therethrough complementary to and receptive of said centering flange and about which said mounting flange seats,

said centering flange having a notch opening therethrough,

an integral projecting portion on said panel extending through said notch opening and into said aperture,

and means securing said projecting portion to said body.

4. In combination, in an electrical socket assembly of the character described,

a dielectrical body of substantial length and diameter having opposite end faces and an integral lateral flange thereabout adjacent to one of said end faces and spaced substantially from the other of said end faces and substantially thinner than the length of the body,

an annular series of receptacle bores extending lengthwise through said body and opening through said opposite end faces closely adjacent to the perimeter of said body,

an annular series of corresponding terminals bores extending through said flange adjacent to the perimeter of the body,

respective receptacle-terminal units each comprising a pin receptacle and a solder well terminal and a connecting tail piece affording a generally U-shaped structure with the receptacle in one of the receptacle bores and the terminal in the corresponding terminal bore and the tail piece extending between the bores at said one end face and connecting respective ends of the receptacle and terminal,

and means cooperating with the tail piece in each instance to retain the associated unit in place,

each receptacle having a pin-receiving mouth accessible through an access end of the associated receptacle bore within the plane of said other of said end faces and the associated terminal having an open end accessible for introduction of a wire lead into its connected end which is adjacent to said one end face,

said solder well terminals being of a length to extend through and beyond said flange along and exposed at the perimeter of the body and with the distal ends of the terminals adjacent to but within the plane of said other end face.

5. In combination, in an electrical terminal supporting dielectric member including a flange portion with an aperture therethrough:

an electrical terminal having an elongated tubular body, one end of which is axially open for entry therethrough of electrical leads to be retained in the terminal and affording an annular mounting base engaged in said aperture;

a shoulder on said body contiguous to said base portion and seated against one face of said flange portion about said aperture;

lug means on the free extremity of said base portion engaging the opposite face of said flange portion about said opening and coacting with said shoulder to secure the terminal to the flange portion;

the opposite end portion of the terminal body having stop means thereacross for engagement by the ends of electrical leads entered into the body through said base portion;

lead-retaining prongs extending into said body convergently and generally toward said stop means;

and a laterally outwardly projecting portion on said body intermediate said shoulder and said stop means but closer to said shoulder and having an inside surface tapering toward said stop means.

6. The combination as defined in claim 5, in which said laterally outwardly projecting portion on said body comprises an annular bulge which tapers generally frustoconically toward said stop means and provides said tapering inside surface, said body having strike-out apertures extending across said bulge and from which said prongs are derived.

7. An electrical tube socket of the character described comprising:

a dielectric body including a central portion of substantial thickness having a substantially thinner flange adjacent to one end of said body portion and spaced from the opposite end of said portion;

said central portion having a perimeter and a first series of bores therethrough spaced inwardly from said perimeter and having entry ends opening through said opposite end of said central portion and said flange having a second series of bores therethrough adjacent to said perimeter and paired with the bores of said first series;

respective electrically conductive connector units each including a pin receptacle in a respective first series bore and disposed for access thereinto through the end of said first series bore which opens from said opposite end of said central portion, and an electrical lead-receiving solder well disposed in the respective paired bore in said second series and projecting from said flange in exposed relation along said perimeter toward but within the plane of said opposite end of said central portion;

and a removably attached masking member on said opposite end of said central portion to prevent entry of solder into said entry ends of said first series of bores but leaving said solder wells exposed to receive solder when dipping said opposite end of said central portion into solder for soldering leads to said solder wells.

8. An electrical tube socket as defined in claim 7, in which said flange includes a pair of oppositely extending ears in the plane of said flange, a respective solder well terminal mounted on each of said ears and projecting in the same direction as said solder wells so as to be soldered simultaneously with said solder wells during said soldering dipping.

9. A tube socket as defined in claim 8 in which each of said terminals has an opening thereinto receptive of an electrical terminal and prong means extending inwardly to engage the terminal, and a laterally outwardly projecting portion on each of said terminals intermediate its ends and spaced from the ear on which the terminal is mounted, said terminals having contiguous to said outwardly projecting portions thereof apertures to the interior thereof.

References Cited by the Examiner UNITED STATES PATENTS 2,291,001 7/1942 Smith 339-193 2,369,541 2/1945 Del Camp 339-193 2,427,991 9/1947 Del Camp 339-193 2,563,775 8/1951 Del Camp 339-193 10 Del Camp 339-193 X Wagner et al 339-193 Gibson 339-14 X Bang 339-275 X Heath 339-14 X Schlee 339-193 Maximotf et a1. 339-275 X Jensen et a1. 339-194 OTHER REFERENCES Allen et a1.: IBM Technical Disclosure Bulletin, July, 1961,'page 9, 33947.

MARVIN A. CHAMPION, Primary Examiner.

15 EDWARD C. ALLEN, ALER ED S. TRASK, RICHARD E. MOORE, Examiners. 

3. IN COMBINATION, A SOCKET ASSEMBLY COMPRISING A DIELECTRIC BODY HAVING FRONT AND BACK FACES AND PROVIDED WITH A LATERAL MOUNTING FLANGE ON ITS BACK END PORTION INCLUDING AN AXIALLY EXTENDING CENTERING FLANGE PROJECTING REARWARDLY THEREFROM, A PLURALITY OF ELECTRICAL RECEPTACLES MOUNTED IN SAID BODY AND HAVING PIN-RECEIVING MOUTH ENDS ACCESSIBLE FROM THE FRONT FACE OF THE BODY AND PROVIDED WITH ELECTRICAL TERMINALS AT LEAST PARTIALLY MOUNTED IN SAID MOUNTING FLANGE AND HAVING LEAD-RECEIVING OPENINGS ACCESSIBLE FROM THE BACK OF THE BODY, A MOUNTING PANEL HAVING AN APERTURE THERETHROUGH COMPLEMENTARY TO AND RECEPTIVE OF SAID CENTERING FLANGE AND ABOUT WHICH SAID MOUNTING FLANGE SEATS, SAID CENTERING FLANGE HAVING A NOTCH OPENING THERETHROUGH, AN INTEGRAL PROJECTING PORTION ON SAID PANEL EXTENDING THROUGH SAID NOTCH OPENING AND INTO SAID APERTURE, AND MEANS SECURING SAID PROJECTING PORTION TO SAID BODY. 